The invention relates to a semiconductor device having a structure effect from that of field originating transistors of a vertical configuration, and with which it is proposed to induce by novel means a deflection of ballistic electrons in such a way as to bring about an extremely rapid switching of a current or signal, or a change in phase of the signal. The invention also relates to a production process for such a device.
It is known that under certain conditions, the electrons which are displaced under an electrical field effect in a semiconductor medium, such as gallium arsenide, indium phosphide or indium-antimonide can, over a distance less than one micron, take paths which are not disturbed in speed and direction by collisions with other particles. These are called ballistic electrons. The transit time of the electrons within the ballistic transport device must be approximately the same as the average relaxation time of an electron beam between incidents leading to a loss of energy through any random mechanism in the semiconductor material.
Vertical transistor structures have been produced in which electrons are channelled, between the fingers of a gate embedded in semiconductor material, and which very rapidly cross the very short distance between the cathode and anode, i.e. between the source and drain of the field effect transistor constituted by the structure. As a result of the partially ballistic behaviour of the electrons, such transistors have a higher maximum frequency and transconductance than conventional transistors. However, such structures cannot be used for performing certain high speed switching functions or for very accurate phase shifting.